Lesson Notes By Weeks and Term v3 - Senior Secondary 2
Animal Nutrition
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Animal Nutrition
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Subject: Agricultural Science
Class: Senior Secondary 2
Term: 3rd Term
Week: 2
Theme: Animal Science
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Classify feeds Mention sources and functions of food nutrients. State the different types of rations/diet and the ir uses. state causes and symptoms of malnutrition and the ir correction in farm animals.
This section provides a detailed explanation of the core concepts related to Animal Nutrition, designed for the teacher's comprehensive understanding. A. Classification of Feeds Animal feeds are generally classified based on their nutritional content and physical characteristics.
1. Concentrates: Definition: Feeds that are rich in energy and/or protein, but low in fibre (typically less than 18% crude fibre). They are highly digestible.
Characteristics: High nutrient density, often expensive.
Types: Energy Concentrates: High in carbohydrates (e.g., maize/corn, sorghum/guinea corn, millet, cassava, rice bran, palm kernel cake). Primary function is to provide energy.
Protein Concentrates: High in protein (e.g., groundnut cake, soyabean meal, fish meal, blood meal, cotton seed cake, sunflower seed cake). Essential for growth and tissue repair. Nigerian
Examples: Maize, sorghum, millet, cassava flour, rice bran (energy); groundnut cake, soyabean meal, palm kernel cake, fish meal (protein).
2. Roughages (Forages): Definition: Feeds that are high in fibre (typically more than 18% crude fibre) and low in digestible nutrients. They provide bulk to the diet, which is particularly important for ruminants.
Characteristics: Low nutrient density, often cheaper, important for gut health and rumination.
Types: Dry Roughages: Hay (dried grasses and legumes), straw (dried stalks of cereals like rice, maize, millet).
Green Roughages (Pasture/Forages): Fresh grasses (e.g., Guinea grass, Elephant grass, Rhodes grass), legumes (e.g., Stylosanthes, Centrosema, Mucuna), fodder crops.
Silage: Fermented green forages stored under anaerobic conditions. Nigerian
Examples: Fresh grasses (e.g., Elephant grass, Andropogon), Stylosanthes, dried maize stover, rice straw, cassava peels, yam peels. B. Sources and Functions of Food Nutrients Farm animals require six essential classes of nutrients for growth, maintenance, and production.
1. Carbohydrates: Sources: Cereal grains (maize, sorghum, millet, rice), root crops (cassava, yam, sweet potato), industrial by-products (molasses, brewers' spent grain), grasses and legumes.
Functions: Primary source of energy for metabolic processes, movement, and heat production. Excess can be stored as glycogen or converted to fat. Fibre (a complex carbohydrate) aids digestion and provides bulk, especially for ruminants.
2. Proteins: Sources: Legume seeds (soyabean, groundnut, cowpea), oilseed cakes (groundnut cake, soyabean meal, palm kernel cake), fish meal, blood meal, milk products, quality pasture.
Functions: Essential for growth and repair of body tissues (muscles, skin, hair, feathers, internal organs). Production of enzymes, hormones, and antibodies. Component of milk and eggs. Can be used as an energy source when carbohydrate intake is insufficient.
3. Fats and Oils (Lipids): Sources: Vegetable oils (palm oil, groundnut oil, soyabean oil), animal fats (tallow, lard), oilseeds (palm kernel, groundnut, soyabean).
Functions: Concentrated source of energy (2.25 times more energy than carbohydrates or proteins per unit weight). Carrier for fat-soluble vitamins (A, D, E, K). Insulation against cold. Protection of internal organs. Component of cell membranes and hormones.
4. Vitamins: Definition: Organic compounds required in small amounts for normal metabolism, growth, and reproduction.
Classification: Fat-soluble vitamins (A, D, E, K): Stored in body fat. Water-soluble vitamins (B-complex, C): Not stored, require regular intake.
Sources: Fresh green forages, pasture, liver, fish oil, yeast, synthetic vitamin supplements.
Functions: Vitamin A: Vision, healthy skin, mucous membranes, reproduction.
Vitamin D: Calcium and phosphorus absorption, bone formation.
Vitamin E: Antioxidant, reproductive health.
Vitamin K: Blood clotting.
B-complex vitamins: Coenzymes in metabolic reactions, energy metabolism, nerve function.
Vitamin C: (Often synthesised by farm animals, but important for young or stressed animals) Antioxidant, immune function.
5. Minerals: Definition: Inorganic elements required for various physiological functions.
Classification: Macro-minerals: Required in larger amounts (e.g., Calcium, Phosphorus, Sodium, Potassium, Chlorine, Magnesium, Sulphur).
Micro-minerals/Trace elements: Required in smaller amounts (e.g., Iron, Copper, Zinc, Manganese, Iodine, Selenium, Cobalt).
Sources: Bone meal, oyster shell, salt licks, mineral supplements, some forages, dicalcium phosphate.
Functions: Calcium & Phosphorus: Bone and teeth formation, eggshell quality, milk production. Sodium, Potassium, Chlorine: Electrolyte balance, nerve impulse transmission, osmotic pressure regulation.
Iron: Component of haemoglobin (oxygen transport).
Iodine: Thyroid hormone production.
Zinc: Enzyme activity, immune function, skin and hair health. (worms, ticks) and diseases can interfere with nutrient absorption and utilisation, even with adequate feed.
Environmental Stress: Extreme heat or cold, overcrowding, and poor housing conditions can increase nutrient requirements or reduce feed intake.
Poor Water Quality/Availability: Lack of clean water hinders digestion and nutrient transport.
2. Symptoms of Malnutrition: General Symptoms: Stunted growth (especially in young animals). Loss of body weight/emaciation. Dull, rough coat/hair/feathers (loss of shine). Reduced productivity (low milk yield, fewer/smaller eggs, poor reproductive performance). Weakness, lethargy, reduced activity. Increased susceptibility to diseases and infections. Delayed onset of puberty.
Specific Nutrient Deficiency Symptoms: Protein Deficiency: Poor growth, poor muscle development, reduced egg/milk production, poor feathering in poultry.
Energy Deficiency: Weight loss, low activity, reduced milk/egg production, ketosis (in severe cases).
Calcium/Phosphorus Deficiency: Rickets (soft bones, lameness) in young animals, osteomalacia (weak bones) in adults, thin-shelled eggs in poultry, milk fever in lactating animals.
Vitamin A Deficiency: Night blindness, poor growth, rough coat, reproductive problems.
Vitamin D Deficiency: Rickets, poor bone calcification.
Iron Deficiency: Anaemia (pale mucous membranes), weakness.
Iodine Deficiency: Goitre (enlarged thyroid gland), poor reproductive performance.
Water Deficiency: Dehydration, reduced feed intake, dry skin, reduced productivity, death.
Pica (depraved appetite): Animals eating non-food items like soil, bones, or chewing wood, often indicating a mineral deficiency (e.g., phosphorus).
3. Correction of Malnutrition: Adjusting Feed Formulation: Reformulating the diet to provide all essential nutrients in the correct balance and quantity according to the animal's age, physiological state, and production level.
Supplementation: Providing specific nutrient supplements (e.g., mineral blocks, vitamin premixes, protein concentrates) to address identified deficiencies.
Improving Feed Quality: Sourcing high-quality raw materials, proper storage of feeds to prevent spoilage (mould growth), and processing (e.g., grinding, pelleting) to improve digestibility and palatability.
Parasite and Disease Control: Regular deworming and vaccination programmes to prevent diseases that impair nutrient absorption.
Providing Clean Water: Ensuring continuous access to fresh, clean drinking water.
Environmental Management: Providing adequate shelter, ventilation, and reducing stress factors to improve feed intake and nutrient utilisation. * Record Keeping: Monitoring feed intake, weight gain, and production records to identify issues early and adjust feeding strategies. --- Classification: Macro-minerals: Required in larger amounts (e.g., Calcium, Phosphorus, Sodium, Potassium, Chlorine, Magnesium, Sulphur).
Micro-minerals/Trace elements: Required in smaller amounts (e.g., Iron, Copper, Zinc, Manganese, Iodine, Selenium, Cobalt).
Sources: Bone meal, oyster shell, salt licks, mineral supplements, some forages, dicalcium phosphate.
Functions: Calcium & Phosphorus: Bone and teeth formation, eggshell quality, milk production. Sodium, Potassium, Chlorine: Electrolyte balance, nerve impulse transmission, osmotic pressure regulation.
Iron: Component of haemoglobin (oxygen transport).
Iodine: Thyroid hormone production.
Zinc: Enzyme activity, immune function, skin and hair health.
6. Water: Sources: Drinking water, moisture content of feeds, metabolic water (produced during nutrient metabolism).
Functions: Solvent and transport medium for nutrients and waste products. Regulation of body temperature (evaporation). Lubrication of joints. Essential for all biochemical reactions in the body. Component of blood, lymph, and tissue fluids. C. Types of Rations/Diets and Their Uses A ration refers to the total amount of food given to an animal in a 24-hour period. A diet refers to the specific mixture of feedstuffs provided.
1. Maintenance Ration: Definition: The amount of feed required by an animal simply to sustain its body weight and vital life processes (respiration, circulation, body temperature regulation) without any production (growth, milk, eggs, work).
Uses: Keeping non-productive animals (e.g., breeding animals not lactating, animals during resting periods) alive and healthy. It prevents weight loss.
2. Production Ration: Definition: The additional feed required beyond the maintenance ration to support various forms of production (e.g., growth, fattening, milk production, egg laying, reproduction, work).
Types and Uses: Growth Ration: Provided to young, growing animals to facilitate muscle, bone, and tissue development. High in protein and energy.
Fattening Ration: Given to animals to promote rapid weight gain and deposition of fat, usually for meat production. High in energy.
Lactation/Milk Production Ration: Provided to lactating animals (e.g., dairy cows, goats) to support milk synthesis. High in protein, energy, calcium, and phosphorus.
Egg Production Ration (Laying Ration): Given to laying birds to support egg formation. High in protein, energy, and calcium (for eggshell).
Work Ration: Provided to working animals (e.g., draught cattle) to meet the energy demands of physical labour. High in energy.
Gestation Ration (Reproduction Ration): Provided to pregnant animals to support foetal development and prepare for lactation. Balanced in all nutrients, particularly protein and minerals.
3. Balanced Ration: Definition: A ration that contains all the essential nutrients (carbohydrates, proteins, fats, vitamins, minerals, water) in the correct proportions and amounts to meet the specific physiological needs of the animal for both maintenance and production.
Importance: Ensures optimal health, growth, production, and feed efficiency. Prevents malnutrition.
4. Unbalanced Ration: Definition: A ration that is deficient in one or more essential nutrients, or contains nutrients in disproportionate amounts, or contains excessive amounts of certain nutrients that can be toxic.
Consequences: Leads to malnutrition, poor performance, reduced productivity, increased susceptibility to diseases, and in severe cases, death.
D. Malnutrition: Causes, Symptoms, and Correction in Farm Animals Malnutrition refers to a condition resulting from an inadequate or unbalanced intake of nutrients, which impairs the normal functioning of the body.
1. Causes of Malnutrition: Inadequate Feed Intake: Insufficient quantity of feed due to scarcity, high cost, poor palatability, or competition among animals.
Poor Quality Feed: Feeds lacking essential nutrients or containing anti-nutritional factors (e.g., mouldy feed, feed with low protein content).
Imbalanced Diet: Deficiency or excess of specific nutrients (e.g., protein deficiency, mineral imbalance).
Disease and Parasitism: Internal and external parasites (worms, ticks) and diseases can interfere with nutrient absorption and utilisation, even with adequate feed.
Environmental Stress: Extreme heat or cold, overcrowding, and poor housing conditions can increase nutrient requirements or reduce feed intake.
Poor Water Quality/Availability: Lack of clean water hinders digestion and nutrient transport.
2. Symptoms of Malnutrition: General Symptoms: Stunted growth (especially in young animals). Loss of body weight/emaciation. Dull, rough coat/hair/feathers (loss of shine). Reduced productivity (low milk yield, fewer/smaller eggs, poor reproductive performance). Weakness, lethargy, reduced activity. * Increased Phase 1: Introduction and Engagement (10 minutes)
Teacher Activity: Recaps previous lesson on "Digestive System of Farm Animals," asking questions about how animals process food. Introduces the new topic, "Animal Nutrition," by posing a thought-provoking question: "Why do we feed animals differently? For example, why is a laying hen fed differently from a broiler chicken?" Briefly explains the importance of proper animal nutrition in Nigerian farming, linking it to animal health and productivity. States the learning objectives for the lesson in clear terms.
Student Activity: Respond to recap questions. Engage in the discussion, sharing their initial thoughts on the introductory question. Listen attentively to the introduction and learning objectives.
Phase 2: Exploration and Explanation (40 minutes)
Teacher Activity: Classification of Feeds: Explains the two main classes of feeds: Concentrates and Roughages. Uses visual aids (charts or actual samples if available, e.g., maize grains, groundnut cake, guinea grass, rice straw) to illustrate examples for each class relevant to Nigerian context. Guides students to identify characteristics.
Food Nutrients: Presents each nutrient class (Carbohydrates, Proteins, Fats/Oils, Vitamins, Minerals, Water) in detail. For each nutrient, explains its primary sources in Nigeria (e.g., maize for carbs, groundnut cake for protein, palm oil for fats) and its key functions in the animal's body. Utilises a table on the board for clarity.
Types of Rations: Defines "ration" and explains different types: Maintenance and Production (Growth, Fattening, Lactation, Egg Production, Work). Emphasises the purpose of each ration, providing examples for different farm animals common in Nigeria (e.g., a maintenance ration for a dry cow vs. a lactation ration for a milking cow).
Malnutrition: Defines malnutrition. Explains the various causes, including poor quality feed, imbalanced diet, diseases, and environmental factors. Presents common symptoms of malnutrition using examples (e.g., stunted growth, rough coat, lameness). Guides students to identify the nutrient deficiency that might cause specific symptoms.
Correction of Malnutrition: Discusses practical steps for correcting malnutrition, such as feed reformulation, supplementation, disease control, and improved water access.
Student Activity: Take notes as the teacher explains. Participate in identifying and describing feed samples. Engage in question-and-answer sessions to clarify concepts. Contribute examples of local feed sources. Discuss in pairs or small groups the implications of different rations. Ask questions about specific symptoms or causes of malnutrition.
Phase 3: Elaboration and Practice (30 minutes)
Teacher Activity: Organises students into small groups (e.g., 4-5 students). Assigns each group a specific task, for instance: Group 1: List 3 Nigerian concentrate feeds and their primary nutrient.
Group 2: List 3 Nigerian roughage feeds and their primary nutrient.
Group 3: Describe the function of protein and one symptom of its deficiency.
Group 4: Explain the difference between a maintenance ration and a growth ration.
Group 5: Suggest two ways a farmer can correct malnutrition in his poultry flock. Circulates among groups, providing guidance, clarifying misconceptions, and ensuring all students participate. Facilitates a whole-class discussion where each group presents their findings, and other groups offer critiques or additions.
Student Activity: Work collaboratively in their assigned groups. Discuss and formulate answers to their assigned tasks. Present their group's findings to the class. Engage in peer-to-peer learning and constructive criticism during presentations.
Phase 4: Evaluation and Conclusion (10 minutes)
Teacher Activity: Administers short oral or written questions based on the lesson objectives (referencing the evaluation guide). Summarises the key points of the lesson, re-emphasising the practical importance of animal nutrition for Nigerian agriculture. Assigns homework related to the topic.
Student Activity: Answer evaluation questions. Listen to the lesson summary. Note down homework assignment. ---
Economic Viability of Livestock Farming (Nigeria's Economy): Proper animal nutrition directly translates to increased productivity (more milk, eggs, meat) and healthier animals, which means higher profits for Nigerian farmers. For example, a farmer who understands how to formulate a balanced feed for his broiler chickens will achieve faster growth rates and better feed conversion ratios, selling his birds quicker and at a better price compared to one whose animals are malnourished. This knowledge empowers farmers to run profitable businesses, contributing to the national economy and reducing reliance on imported animal products.
Food Security and Community Health: By ensuring optimal animal health and productivity through balanced nutrition, the availability of animal protein (meat, eggs, milk) in Nigerian communities is enhanced. This directly impacts food security and improves the nutritional status of the human population, especially children, in a country where protein deficiency remains a public health concern. For instance, increased local production of eggs due to proper layer nutrition makes eggs more affordable and accessible to families. Sustainable Resource Utilisation and Entrepreneurship: The classification of feeds and understanding nutrient sources encourages the use of locally available feed ingredients (e.g., maize, cassava peels, groundnut cake, rice bran) in Nigeria. This reduces transportation costs, supports local agricultural economies, and promotes sustainable practices. Learners can explore entrepreneurial opportunities in local feed milling, advising farmers on feed formulation, or even engaging in commercial production of specific nutrient supplements. For example, setting up a small business to produce quality fish meal from local fish by-products or formulating mineral licks for ruminants. ---